Control system and user interface for an ablation system

ABSTRACT

Electrosurgical generators having improved functionality and user interface. In an example, the user may modify therapy output parameters without interrupting therapy delivery within a therapy regimen. In an example, the display shows both therapy amplitudes and encountered impedances for a plurality of therapy pulses in different portions of a display. In an example, the electrosurgical generator is operable in a triggered mode using a cardiac signal trigger and provides the operator with an estimate of remaining time that is calculated in light of a calculated cardiac rate.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application claims the benefit of and priority to U.S.Provisional Application No. 62/915,489, titled CONTROL SYSTEM AND USERINTERFACE FOR AN ABLATION SYSTEM, filed Oct. 15, 2019, the disclosure ofwhich is incorporated herein by reference.

BACKGROUND

Removal or destruction of diseased tissue is a goal of many cancertreatment methods. Tumors may be surgically removed, however, lessinvasive approaches garner much attention. Tissue ablation is aminimally invasive method of destroying undesirable tissue in the body.A variety of ablation techniques have been developed, many using theapplication of electricity or other energy via a probe placed on orinserted into or adjacent target tissue. For example, heat-based thermalablation adds heat to destroy tissue. Radio-frequency (RF) thermal,microwave and high intensity focused ultrasound ablation can each beused to raise localized tissue temperatures well above the body's normal37 degrees C. Irreversible electroporation (IRE) uses electric fields toexpand pores in the cell membrane beyond the point of recovery, causingcell death for want of a patent cell membrane. The spatialcharacteristics of the applied field control which cells and tissue willbe affected, allowing for better selectivity in the treatment zone thanwith thermal techniques. IRE typically uses a narrower pulse width thanRF ablation to reduce thermal effects.

User interfaces and control systems for ablation procedures havehistorically been either highly technical, requiring a very skilledoperator to use, or rudimentary. As multiple different approaches toablation are developed, new and alternative control systems and userinterfaces are desired.

OVERVIEW

The present inventors have recognized, among other things, that aproblem to be solved is the need for new and/or alternative userinterfaces and control systems that provide control over the parametersneeded by the user to define different ablation techniques withoutunnecessarily complicating procedure setup and control.

An illustrative, non-limiting apparatus example takes the form of anelectrosurgical generator comprising: one or more ports adapted toreceive one or more electrosurgical probes, each port comprising atleast one contact; a high voltage power source; delivery circuitrycomprising a plurality of switches configured to route an output fromthe power source to selected contacts of the one or more ports; acontroller having stored instructions that can be selected, configuredor adjusted by a user, the stored instructions including at least oneinstruction set for delivering a therapy regimen, the therapy regimencomprising a plurality of pulses each having a pulse amplitude and apulse width, the instruction set defining the pulse amplitude and thepulse width and optionally pulse repetition rate; and a user interfacehaving a user operable change tool that the user can actuate to modifythe pulse amplitude without stopping or interrupting the therapyregimen.

Additionally or alternatively, the high voltage power source comprisesat least first and second capacitors configured for outputting therapypulses, and a stack selector comprising a plurality of switchesresponsive to the change tool to include, in a first configuration, allof the capacitors for purposes of outputting therapy pulses, and in asecond configuration, less than all of the capacitors for purposes ofoutputting therapy pulses.

Additionally or alternatively, the high voltage power source is coupledto a voltage step down circuit responsive to the change tool to route ahigher or lower voltage from the high voltage power source to thedelivery circuitry.

Additionally or alternatively, the instruction set for delivering thetherapy regimen comprises a series of pulses grouped as a burst, thetherapy regimen defining how many pulses are in a burst and, optionally,a burst repetition rate, wherein the controller further comprises anexecutable triggering instruction set adapted to receive or identify atherapy trigger, identify a therapy window for delivery of a therapyburst from within the therapy regimen relative to the therapy trigger,and instruct the delivery circuit to route a therapy burst to selectedcontacts of the one or more ports.

Additionally or alternatively, the instruction set for delivering thetherapy regimen comprises a series of pulses grouped as a burst, thetherapy regimen defining how many pulses are in a burst, furthercomprising a trigger circuit adapted to sense or receive arepresentation of a cardiac signal of a patient, identify a therapywindow for delivery of a therapy burst from within the therapy regimen,and instruct the delivery circuit to route a therapy burst to selectedcontacts of the one or more ports.

Another illustrative, non-limiting apparatus example takes the form ofan electrosurgical generator comprising: one or more ports adapted toreceive one or more electrosurgical probes, each port comprising atleast one contact; a high voltage power source; delivery circuitrycomprising a plurality of switches configured to route an output fromthe power source to selected contacts of the one or more ports; acontroller having stored instructions that can be selected, configuredor adjusted by a user, the stored instructions including at least oneinstruction set for delivering a therapy regimen, the therapy regimendefining a multi-polar output sequence in which at least threeelectrodes are used, with a first selection of the electrodes used todeliver a first pulse and a second selection of the electrodes,different from the first selection of the electrodes, used to deliver asecond pulse; a measurement circuitry configured to measure impedanceduring delivery of a therapy pulse including one or more of a currentsensor or a voltage sensor; a user interface configured for displayingtherapy delivery parameters during or after generation of the therapyregimen, the user interface displaying in the amplitude of the firstpulse and the second pulse in a first portion of the user interface andimpedance encountered by the first and second pulses in a second portionof the user interface, to facilitate comparison of the first and secondpulse amplitudes and impedances.

Additionally or alternatively, the controller further comprises anexecutable triggering instruction set adapted to sense or receive arepresentation of a cardiac signal of a patient, identify a therapywindow for delivery of a therapy burst from within the therapy regimen,and instruct the delivery circuit to route a therapy burst to selectedcontacts of the one or more ports.

Additionally or alternatively, the electrosurgical generator furtherincludes a trigger circuit adapted to sense or receive a representationof a cardiac signal of a patient, identify a therapy window for deliveryof a therapy burst from within the therapy regimen, and instruct thedelivery circuit to route a therapy burst to selected contacts of theone or more ports.

Another illustrative, non-limiting apparatus example takes the form ofan electrosurgical generator comprising: one or more ports adapted toreceive one or more electrosurgical probes, each port comprising atleast one contact; a high voltage power source; delivery circuitrycomprising a plurality of switches configured to route an output fromthe power source to selected contacts of the one or more ports; acontroller having stored instructions that can be selected, configuredor adjusted by a user, the stored instructions including at least oneinstruction set for delivering a therapy regimen, the therapy regimencomprising a series of pulses each having a pulse width, the series ofpulses forming a burst, the instruction set defining how many pulses arein each burst and defining how many bursts are to be delivered in thetherapy regimen and, optionally, one or more of a pulse repetition rateand/or a burst repetition rate; a trigger adapted to sense or receive atriggering signal from a patient, the trigger configured to identify atherapy window for delivery of a burst defined by the therapy regimenand command the delivery circuitry to route the output to selectedcontacts during the therapy window, wherein the controller furtherincludes a stored timer instruction set adapted to determine timeremaining for the therapy regimen by determining a trigger rate usingdata from the trigger, and calculate how much time will be required tocomplete remaining bursts of the therapy regimen in light of the triggerrate; and a user interface having a display section that displays to auser an estimated remaining time as calculated by the controllerexecuting the stored timer instruction set.

Additionally or alternatively, the trigger is a dedicated circuit and alead system having electrocardiogram (ECG) electrodes thereon forcapturing a cutaneous cardiac signal from a patient, the dedicatedcircuit including a cardiac signal detector for detecting components ofthe cardiac signal and thereby detecting cardiac cycles.

Additionally or alternatively, the trigger is a stored triggerinstruction set operable by the controller, the electrosurgicalgenerator comprising a wireless transceiver comprising an antenna,amplifier, and demodulator to facilitate receipt of a wireless signalfrom an ECG detector issuing cardiac signal related data includingindications of when a selected component of the cardiac signal occurs,wherein the controller is configured to receive cardiac signal relateddata from the wireless transceiver while executing the stored triggerinstruction set.

Additionally or alternatively, the trigger is configured to wait forexpiration of user configurable delay period after a triggering signalis observed or received before the therapy window, and the userinterface allows the user to select the configurable delay period.

Additionally or alternatively, the user interface comprises an amplitudedisplay allowing the user to set or adjust therapy amplitude and, inconjunction with the amplitude display, the user interface is alsoadapted to display an estimate of the amplitude that will be deliveredto tissue between a selected pair of electrodes on a probe coupled tothe one or more ports.

Additionally or alternatively, the user interface comprises a waveformselector allowing a user to select from at least biphasic and monophasicwaveform types.

Additionally or alternatively, the user interface comprises a waveformdesign tool allowing a user to select an interval between pulses in eachburst, a quantity of pulses to provide in each burst, and a quantity ofbursts to deliver, and the controller is responsive to the waveformdesign tool to select, configure, or adjust an instruction set definingthe therapy regimen.

Additionally or alternatively, the controller is configured to storefirst and second therapy logs for delivery of the therapy regimen asfollows: the first log comprising input and output parameters of therapyas delivered; and the second log recording raw waveforms as delivered tothe patient.

Additionally or alternatively, the user interface comprises a pausebutton or icon operable to interrupt a therapy regimen withoutterminating the therapy regimen.

Some illustrative, non-limiting system examples take the form of asystem for treating a patient by ablation of a target tissue comprisingan electrosurgical generator as any of the preceding illustrative,non-limiting apparatus examples, and a probe configured for use with theelectrosurgical generator.

An illustrative, non-limiting method example takes the form of a methodof treating a patient by ablation of a target tissue using anelectrosurgical generator having a user interface, the methodcomprising: initiating a therapy regimen comprising a series of pulseseach having a pulse amplitude and a pulse width; and actuating a useroperable change tool accessible via the user interface to modify thepulse amplitude without stopping or interrupting the therapy regimen.The therapy regimen may further define one or more of a pulse repetitionrate and/or a burst repetition rate.

Additionally or alternatively, the electrosurgical generator comprises ahigh voltage power source having at least first and second capacitorsconfigured for outputting therapy pulses, and a stack selectorcomprising a plurality of switches responsive to the change tool toinclude, in a first configuration, all of the capacitors for outputtingtherapy pulses, and in a second configuration, less than all of thecapacitors for outputting therapy pulses, wherein the step of actuatingthe user operable change tool causes switching of the electrosurgicalgenerator between the first and second configurations.

Additionally or alternatively, wherein the electrosurgical generatorcomprises a high voltage power source and a voltage step down circuitresponsive to the user operable change tool to route a higher or lowervoltage from the high voltage power source to the delivery circuitry.

Additionally or alternatively, the therapy regimen is a triggeredtherapy regimen making use of a triggering circuit in theelectrosurgical generator or a stored instruction set operable by theelectrosurgical generator for providing triggered therapy using abiological signal.

Another illustrative, non-limiting method example takes the form of amethod of delivering ablation therapy to a patient in an electrosurgicalgenerator having one or more ports adapted to receive one or moreelectrosurgical probes, each port comprising at least one contact; ahigh voltage power source; delivery circuitry comprising a plurality ofswitches configured to route an output from the power source to selectedcontacts of the one or more ports; a controller having storedinstructions that can be selected, configured or adjusted by a user, thestored instructions including at least one instruction set fordelivering a therapy regimen, the therapy regimen defining a multi-polaroutput sequence in which at least three electrodes are used, with afirst selection of the electrodes used to deliver a first pulse and asecond selection of the electrodes, different from the first selectionof the electrodes, used to deliver a second pulse; a measurementcircuitry configured to measure impedance during delivery of a therapypulse including one or more of a current sensor or a voltage sensor; auser interface configured for displaying therapy delivery parametersduring or after generation of the therapy regimen, the methodcomprising: delivering at least the first and second pulses; measuringimpedance encountered by each of the first and second pulses; displayingin the amplitude of the first pulse and the second pulse in a firstportion of the user interface; and displaying impedance encountered bythe first and second pulses in a second portion of the user interface,thereby facilitating comparison of the first and second pulse amplitudesand impedances.

Additionally or alternatively, wherein the therapy regimen is atriggered therapy regimen making use of a triggering circuit in theelectrosurgical generator or a stored instruction set operable by theelectrosurgical generator for providing triggered therapy using abiological signal.

Another illustrative, non-limiting method example takes the form of amethod of operation in an electrosurgical generator having one or moreports adapted to receive one or more electrosurgical probes, each portcomprising at least one contact; a high voltage power source; deliverycircuitry comprising a plurality of switches configured to route anoutput from the power source to selected contacts of the one or moreports; a controller having stored instructions that can be selected,configured or adjusted by a user, the stored instructions including atleast one instruction set for delivering a therapy regimen, the therapyregimen comprising a series of pulses each having a pulse width, theseries of pulses forming a burst, the instruction set defining how manypulses are in each burst and defining how many bursts are to bedelivered in the therapy regimen; a trigger adapted to sense or receivea triggering signal from a patient, the trigger configured to identify atherapy window for delivery of a burst defined by the therapy regimen;the method comprising: delivering at least two therapy bursts inresponse to at least two triggering signals; determining a trigger rateusing data from the trigger; calculating how much time will be requiredto complete remaining bursts of the therapy regimen in light of thetrigger rate; and displaying via the a user interface an estimatedremaining time as calculated by the stored timer instruction set.

Additionally or alternatively, the trigger relies on cutaneous cardiacsignal from a patient, such that the estimated remaining time relates tocardiac cycle rate of the patient.

Additionally or alternatively, the method further comprises displayingeach of a programmed amplitude and a delivered amplitude for therapypulses.

Additionally or alternatively, the user interface comprises a waveformselector allowing a user to select from at least biphasic and monophasicwaveform types.

An illustrative non-limiting user interface example takes the form of auser interface for an electrosurgical generator having a power supply,output circuitry, one or more ports for receiving an electrosurgicalprobe or probes, and control circuitry adapted to execute storedinstructions to deliver bursts of therapy pulses, the user interfacecomprising a user selectable waveform type tool including each of thefollowing: monophasic waveform type; biphasic waveform type, in whicheach therapy pulse comprises first and second phases each using the sameelectrodes but in opposite polarity; and three electrode rotating type,in which each therapy pulse comprises first, second and third phasesusing each of first, second and third electrode combinations; whereinthe user interface presents options for each of the three waveformtypes, depending on which waveform type is selected, to the user todefine the following: for a monophasic waveform type, amplitude, pulsewidth, and electrode selection for each monophasic pulse, a quantity ofmonophasic pulses and interpulse intervals to use in a burst, and anumber of bursts to be delivered; for a biphasic waveform type,amplitude, pulse width, interphase delay and electrode selection foreach biphasic pulse, a quantity of biphasic pulses and interpulseintervals to use in a burst, and a number of bursts to be delivered; andfor a three electrode rotating type, selection of first, second andthird electrode combinations for the first, second and third phases,amplitude, pulse width and interphase periods, a quantity of therapypulses and interpulse intervals to use in each burst.

Another illustrative, non-limiting method example takes the form of amethod of displaying a therapy status in an ablation system whiledelivering therapy, the method comprising: initially determining aquantity of pulse bursts to be delivered, in which each pulse burstcomprising a plurality of individual pulses; sensing a cardiac signal;initiating delivery of the quantity of pulse bursts, each pulse burstbeing delivered in a window between sensed cardiac events; displaying toa user each of a quantity of pulse bursts remaining and an estimatedtime remaining in the therapy, wherein the estimated time remaining iscalculated by determining a cardiac rate and multiplying the cardiacrate by the number of pulse bursts remaining.

This overview is intended to provide an introduction to the subjectmatter of the present patent application. It is not intended to providean exclusive or exhaustive explanation of the invention. The detaileddescription is included to provide further information about the presentpatent application.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings, which are not necessarily drawn to scale, like numeralsmay describe similar components in different views. Like numerals havingdifferent letter suffixes may represent different instances of similarcomponents. The drawings illustrate generally, by way of example, butnot by way of limitation, various embodiments discussed in the presentdocument.

FIG. 1 illustrates a user interface for an electrosurgical apparatus;

FIGS. 2, 3, 4A-4D, 5A-5B, 6 and 7 show details of illustrative userinterfaces with reference to FIG. 1;

FIG. 8 illustrates another user interface for an electrosurgicalapparatus;

FIG. 9 highlights a feature of a user interface with reference to FIG.8;

FIGS. 10A-10B show illustrative circuitry facilitating the feature ofFIG. 9;

FIGS. 11A-11B highlight features of a user interface with reference toFIG. 8;

FIG. 12 illustrates in block form an electrosurgical apparatus;

FIG. 13 shows illustrative therapy electrodes;

FIGS. 14A-14C show additional illustrative therapy program interfaces;and

FIG. 15 shows an illustrative method of therapy delivery and statusreporting.

DETAILED DESCRIPTION

FIG. 1 illustrates a user interface for an electrosurgical apparatus.Several section of the user interface are shown with a border and willbe discussed in greater detail below. Area 2 shows the output signalmode and is further described with reference to FIG. 2. Area 3illustrates a voltage control in two parts: the generated (internal)signal and the in-tissue signal amplitudes, and is further describedwith reference to FIG. 3. Area 4 illustrates reporting of programmedvoltage output and sensed current flow, along with programmed parametersfor pulse width, delay and other features, and is further described withreference to FIGS. 4A-4C. Area 5 shows graphical illustration ofimpedances and is further described with reference to FIGS. 5A-5B. Area6 shows active/inactive status and reports on the time remaining for atherapy regimen and is further described with reference to FIG. 6.

Area 8 illustrates the stored capacitor bank voltage in graphic form aswell as with an exact number. As discussed below relative to FIG. 12,the electrosurgical apparatus may be designed with a capacitor bank thatis charged to a relatively high voltage, in the hundreds or thousands ofvolts. The text immediately below area 8 provides a warning indicatorthat high voltage is present in the capacitor bank when a threshold“high voltage” is exceeded, such as 60 volts. In the example shown, atop stored voltage is in the range of about 6000 volts; higher or lowermaximum values may be used, such as in the range of 1000 to 20,000volts, or more or less.

Area 9 provides a historical record of the capacitor bank voltage and isoptional.

In the example of FIG. 1, the graphical user interface may be providedon a touchscreen and/or may be on a monitor used in association withuser input devices well known in the art, such as a keyboard and mouseor trackball.

The electrosurgical apparatus may also be referred to as a signalgenerator. In a typical use configuration, one or more probes areplugged into the electrosurgical apparatus, with the probes theninserted into the patient or placed on the patient at a location incontact with, within, or adjacent to tissue to be treated such as anidentified tumor, malignancy, or biological structure to be ablated. Areturn electrode may be placed on the patient elsewhere, such as with acutaneous pad electrode, with the return electrode also coupled by wireto the electrosurgical generator. The probe or probes may have one ormore electrodes thereon for outputting an electrical signal at a targetposition relative to the tissue to be ablated.

FIG. 2 illustrates the output signal mode selection of the system,highlighted as area 2 in FIG. 1. In this example, selecting the signalmode icon, such as by moving a mouse pointer and clicking or by touchinga touchscreen brings up a dropdown list of signal modes that can beused. In this example, three modes are shown, including monophasic,biphasic and “3 electrode rotating” configurations.

A monophasic signal mode is one in which therapy electrodes on a probeused with the electrosurgical apparatus are used to deliver an output ofa polarity, using one or more therapy electrodes on the probe as anode,and one or more other therapy electrodes on the prove as cathode. Aseparate return electrode pad may be used along with or in place of atherapy electrode on the probe for either anode or cathode, as desired.The output can have a pulse width and amplitude, but is not associatedwith a polarity reversal as would be the case with a biphasic signalmode.

As suggested in the preceding paragraph, a biphasic signal mode is onein which the output is delivered to a defined anode/cathode combinationand, following delivery of a first pulse, an opposite polarity pulse isdelivered. The anode electrodes become cathodes, and the cathodeelectrodes become anodes, in the second phase of a biphasic output.

The three electrode rotating configuration is one in which a sequence ofthree pulses are delivered as a combination using different selectionsof probe therapy electrodes and the return electrode pad for each phase.For example, with reference to FIG. 13, three electrodes A, B, C areshown. Following are some of the three-electrode rotating sequences thatcan be used:

Anode Cathode Indifferent A B C B C A C A BIn this example, any of A, B or C may be a probe electrode or a returnelectrode. In another example:

Anodes Cathode Indifferent A, B C Return A, C B Return B, C A ReturnHere, each of A, B and C may be probe electrodes, while the indifferentelectrode is a return electrode placed elsewhere on the patient.Providing an automated mode for a three electrode rotating configurationmakes programming the system to provide a spatially and/or timemultiplexed output easier than is possible with prior systems. The threeelectrode rotating approach is optional and may be omitted.

In another example, rather than a drop down menu, the user may bebrought to a separate screen to define simple or complex waveformshaving any number of phases with selectable electrodes for each phase.The programming sequence may be as shown in FIG. 14A. The user fills inthe data as shown in the row for phase 1, and then clicks or taps on theicon for “Add Another” to create another phase, as shown by FIG. 14B.For each pulse within the waveform, the user can define, for example andwithout limitation, pulse width, pulse amplitude, and a duration of“off” time that follows the pulse before the start of a subsequentpulse. The “off” time may be omitted for the final pulse in thesequence, or may be treated as an inter-waveform off period. If the userhas completed the waveform definition, the user can select the “Finish”icon. Additional columns may be provided to allow a user to defineadditional features, such as pulse shape (decaying, ramped, etc.). Theinterface may apply limits to the entries provided with reference tosafety, usability, feasibility or other boundary conditions such as bylimiting the maximum amplitude, minimum or maximum pulse width, maximumelectrode usage. Such limits may apply to individual pulses as well asto an overall waveform, such as by limiting the amount of currentimbalance through any given electrode or limiting duty cycle of a givenelectrode. In the example shown, Amplitude is indicated in terms ofvolts; a current-based Amplitude may be used instead, or a mix ofamplitude and current defined pulses may be used.

FIG. 14C shows another example. Here, the chart 20 is provided next toan image 22 that may aid in planning a therapy configuration. The image22 includes a visual representation of a body organ 24 with a targettissue region 26 highlighted. Region 26 may be, for example, a tumor,and the image 22 may be imported electrically from a visualizationsystem such as an ultrasound scanner that may be used preoperatively oras part of an operation itself to assess the target 26, for example byusing a thumb drive or by wireless communication such as WIFI orBluetooth. The letters A, B, C and D may illustrate target positions forthe therapy electrodes. An image of the probe 28 may be provided as wellfor reference purposes.

FIG. 3 illustrates a voltage control, and is highlighted as area 3 inFIG. 1. In this example, the voltage control is shown in two partshaving the generated (internal) signal at 30, and the in-tissue signalamplitude that is applied as the therapy output at 32. The voltage isshown as a slider 34 on a scale of up to 6000 volts, though theavailable range of voltages is merely illustrative of one example. Otherscales and top voltages may be used. In other examples a current maximumis shown rather than a voltage maximum, in which case the separate scaleof the current as delivered would likely be omitted. In this example,the user can use a touchscreen, mouse, or other interface to move theslider 34 up and down to modify the available voltage. If the user wouldrather enter the voltage as text, a text box is provided at 36.

FIGS. 4A-4C illustrates portions of a display having each of programmedparameters and the reporting of output voltage and current, and ishighlighted as area 4 in FIG. 1. The reported information variesdepending on the waveform type, with FIG. 4A representing a monophasicoutput, FIG. 4B representing a biphasic output, and FIG. 4C showing athree-electrode rotating output.

A voltage controlled output is shown in the illustrative example. Forthis example and all others herein, current control or power control maybe used instead. Such systems may deliver constant voltage, current orpower, in some examples, though any of voltage, current or power can becontrolled in a non-constant fashion instead, if desired. For example, aramped output may be generated. In some examples outputs can begenerated from charged capacitors in a manner that allows the outputvoltage to droop, degrade, or decay over time as the charged capacitorsare at least partly discharged during therapy output. The displaysillustrated may be adjusted for current or power control and/or fordisplaying using units of current, power, energy, voltage, and/orimpedance, in other examples.

Starting with FIG. 4A, the user interface for a monophasic output shows,during therapy, pulse width 40, pulses per burst 42, intercycle delay 44and the number of bursts to deliver 46. In a triggered mode, theseparameters will determine what therapy is delivered to the patient inresponse to each triggering event. For example, if the triggering eventis a detected cardiac cycle R-wave, one burst is delivered after eachR-wave detection, with the burst having the number of pulses defined at42, the pulses being separated in time by the intercycle delay 44. If anon-triggered therapy output is defined, an interburst delay may bedefined as well.

A graphical display of a selected burst delivery is shown at 50, withthe generated voltage shown for each of the output pulses in the burst.In the lower box 52, the sensed current for each pulse is shown alongthe same timeline as the voltage display at 50. In this example theupper box shows voltage and the lower box shows current; in otherexamples one box may show any of voltage, current, power, or impedance,while the other box may show a different one of voltage, current, poweror impedance. In some examples, the values shown may vary within thepulse width to account for changes in the current, voltage, impedance orpower during the duration of the pulse. In some examples, the height ofeach pulse may represent an initial value, an average value, a mid-pulsevalue, or an end-of-pulse value for the reported or measured parameter.

The display of FIG. 4A includes on the far right reporting of the peakvoltage 60, peak current 62, and peak impedance 64. In this example, thereported peak voltage 60 is that which is delivered within the tissueand is calculated by measuring the delivered current output 62 and thenusing the known impedances of the signal generator and probe to subtractvoltage loss that occurs before the signal is delivered. Likewise, thecalculated peak impedance 64 can be determined using the current outputto calculate total impedance and then subtracting the known impedancesof the signal generator and probe. To facilitate such calculations,probe impedance may be tested prior to delivering therapy using a testapparatus, or probe impedance may be determined by the use of a look-uptable based on the type of probe in use. The type of probe in use may bedetermined by user input or may be determined by the use of asmart-probe interface on the ports of the signal generator, which couldidentify the type of probe by having the probe include a specializedport interface unique to the probe type, or by including an RFID tag onthe probe and an RFID reader in/near the port for receiving the probe onthe signal generator, for example.

FIG. 4B shows another interface, here tailored for a biphasic mode. Onthe right side, the therapy delivery parameters are now more fullypopulated, including each of a positive pulse width 70, negative pulsewidth 72, interpulse delay 74, pulses per burst 76, intercycle delay 78,and number of bursts. In the example, the signal output would be afirst, positive pulse phase with a pulse width defined at 70, followedby an interpulse delay period defined at 74, followed by a negativepulse phase of opposite polarity to the positive pulse phase having thepulse width defined at 72, followed by an intercycle delay defined at78. That sequence would be repeated by the number of pulses per burstdefined at 76 to complete each burst. As before, the number of bursts todeliver indicates a triggered delivery. If a non-triggered therapyoutput is defined, an interburst delay may be defined as well; duringtriggered therapy there is no need for an interburst delay as thatduration is replaced with the trigger.

In an alternative, multiple bursts may be delivered in response to onetriggering event, such as 2, 3, 4 or more bursts, and an interburstdelay may be defined for a triggered therapy in such an example. Thequantity of bursts that may be delivered in response to a triggeringevent may be set to maximize the use of a defined therapy window thatfollows a triggering event. For example, if the occurrence of an R-waveor other cardiac signal is used as a trigger, and the window for therapyis selected as the S-T segment, a window for therapy may be in the rangeof 5 to 150 milliseconds, depending on heart rate. If a burst comprises100 biphasic cycles, with each cycle consuming 8 microseconds, then theburst can be completed in under 1 milliseconds, allowing several burststo be delivered in a single therapy window. Thus the number of bursts tobe delivered, in a triggered therapy window, as well as an interburstdelay, may also be included as programmable parameters in some examples.Such parameters may be displayed below element 80.

The user interface shows the voltage output at 90 in this example for agiven burst. Impedances of each delivered phase of the burst aregraphically shown at 92 along the same timeline as used at 90. Thenumerical results are shown on the right, with the positive peak voltage100, negative peak voltage 102, positive peak current at 104, andimpedance at 106. If desired, negative peak current may also be shown.The impedance shown at 106 is for the first positive phase output of thesequence; in other examples, a negative phase impedance may be shown aswell.

FIG. 4C shows another interface, this time tailored to a three-electroderotating therapy configuration. In this configuration, three outputpulses are delivered in a series, each using a different selection ofelectrodes than the immediately preceding pulse. Tables for illustrativethree-electrode rotating therapy outputs are shown above. In the exampleof FIG. 4C, the pulse delivery parameters are shown on the left side,with the pulse width of each of the output pulses selected/displayed at120, the inter-pulse delay at 122, the number of pulses in each burst at122, the intercycle delay at 126, and the number of bursts to deliver at128. In this example, each of the pulses is delivered using the sameoutput voltage, pulse width, and interpulse delay period. The exampleshown would deliver three pulses in sequence, twice, within each burst.

The graphic representations 140 and 142 show the sensed deliveredvoltage of each pulse at 140, and the current delivered at 142. In thisexample, the voltages shown at 140 are corrected to account for systemand line losses in the output voltage and so, as can be observed,delivered current for the first of each set of three pulses is higher,causing larger line losses and a lower delivered voltage, than the othertwo pulses in the sequence. By illustrating the voltage and current foreach delivered pulse on one timeline, the operator can see thedifferences in outputs for each of the different therapy outputelectrode combinations.

On the far right, additional details are shown in text form, with thepeak voltage for the first pulse noted at 150, the peak current of thefirst pulse at 152, and the impedance of each pulse shown at 154, 156,158. Other selections of parameters to show may be selected/displayed inother embodiments. In one example, the text box may show all three peak,average, or minimum voltages, current, or impedances of the deliveredoutput, either as a set of 9 values in table form, or in a fashionallowing a user to cycle through the set of parameters by tapping anicon or other actuation.

FIG. 4D shows another alternative, here allowing a user to select aparticular pulse out of a multiphasic therapy to monitor the voltageand/or impedance over time using a selector or slider as shown at 160.In this example, the user is provided with the option to select aparticular phase or pulse of a multiphasic therapy output along tracker160. The example shown allows the user to pick any of the 1^(st), 2^(nd)or 3^(rd) pulse of a triphasic output, such as that shown in FIG. 4C;more or fewer phases may be used in a particular therapy and theinterface at 160 may adjust to the number of phases in use. Thedelivered voltages are shown at 162; in this example, the output(selected) voltage, without correction for line losses, is shown at 162.Sensed impedance is shown in the lower chart at 164, with the Y-axis ofthe two charts 162, 164 being based on the delivered burst/cycle, ratherthan using time along the Y-axis as is used in other examples.

By selecting one of the phases to highlight, the operator can see andunderstand how impedance is changing for a particular combination ofelectrodes and/or polarity. If desired, a trendline 166 may be shown. Ingeneral the impedance in a tissue region goes down as ablation therapyprogresses, due to breakdown of cellular membranes and the release ofintra-cellular fluid, which reduces impedance in the tissue volume. Atrend of impedance dropping over time, as shown, suggests that therapyis progressing well in the particular volume. The operator may select toreduce the applied voltage, or omit the particular phase of therapy, asthe impedance drops to prevent excess current from flowing andpotentially causing undesired ablation away from the target, such as bythe transmission of excess thermal energy due to increasing currentflow.

In another example, the electrosurgical generator may be configured tomodify therapy parameters in response to the impedance. For example, asimpedance goes down over time, the system may automatically reduce theissued therapy signal amplitude, to avoid excess current and heating astherapy progresses.

FIGS. 5A-5B shows graphical illustration of impedances corresponding toArea 5 of FIG. 1. In one example, shown in FIG. 5A, impedance formonophasic or standard biphasic outputs is shown on a graph at 200, witha line for the impedance at 202. Here, the impedance of a single pulseis shown. The example interface allows the user to select amongimpedance over time 204, single session impedance 206, and burstimpedance 208, with each showing a different set of details. Impedanceover time 204 may display impedance from a plurality of therapy“sessions” each comprising a defined number of bursts or duration oftherapy. Impedance in a session 206 may show the impedance during thecourse of a single session having a defined quantity of bursts orduration of therapy. Impedance for the burst 208 may show impedance forseveral individual pulses delivered within a burst.

FIG. 5B shows another example, this time for a multiple pulse or phaseoutput. In this example, the impedances across each of a plurality ofelectrode combinations are shown, corresponding, for example, to a threeelectrode rotating therapy. In this example, a graphic display 220 showsthe impedance for each of three different electrode combinations on thesame vertical scale. The Y-axis here is shown in terms of time, but thestart time for each of the plurality of pulses is aligned. A key 222uses different patterns and/or colors for each of the plurality ofelectrode combinations, with the pulses shown in the graphic display at220 as lines 224, 226, 228. More or fewer pulses may be shown.

FIG. 6 illustrates a graphic display showing system status and timeremaining for a therapy regimen, corresponding to area 6 of FIG. 1. Afirst area 250 displays the status of the electrosurgical apparatus,including whether the high voltage circuitry is active (“HV Active”),whether control circuitry is active (“24V Active”), and whether thedevice is engaged in issuing therapy cycles (“Cycles Active”). Inanother region 252, the estimated time remaining is illustrated, as wellas the trigger rate (here, a cardiac rate), with the time remaining at254 and the heart rate at 256. FIG. 15 shows an illustrativemethod/process for calculating time remaining. The input impedance isillustrated at 258 as well and represents the line or system impedancethat will apply to output currents, which is used to calculate thedifference between voltage as applied the tissue and the voltagegenerated by the high voltage power source of the electrosurgicalapparatus.

The value at 258 may be entered by an operator, or it may be calculatedusing known capabilities of the electrosurgical apparatus and knowncharacteristics of a probe used with the electrosurgical apparatus.Characteristics of the probe may be determined from a look-up table,using, for example, model or serial numbers of the probe entered by auser, or, if a smart-port/probe configuration is used, by reading suchinformation from the probe itself. In some example, characteristics ofthe probe may be entered manually or stored in the memory of theelectrosurgical apparatus.

Turning now to FIG. 15, a method of therapy delivery with tracking andupdating time remaining is illustrated. This may be referred to as atiming means for calculating remaining time. FIG. 15 illustrates aprocess that may be stored as a set of instruction for operating, atleast in part or integrated into a larger process, the electrosurgicalapparatus. Here, a triggering signal is received at 270, which may be,for example, a cardiac signal or any other signal useful for determiningwhen to deliver therapy, such as a temperature sensor output used toensure that the tissue a probe is in or adjacent to remains in a desiredtemperature range. In one branch of the process, therapy delivery occursby setting a window 272 relative to the triggering signal and deliveringone or more bursts of therapy as indicated at 274. In the other branch,a rate at which the triggering event(s) are occurring is received alongwith the triggering signal (such as when a cardiac monitor provides botha calculated cardiac rate and a cardiac trigger signal), or the rate oftriggering event being received is calculated, as indicated at 276. Thetime remaining is then calculated by taking the rate, whether calculatedor received, multiplied by the number of bursts that remain to bedelivered, as indicated at 278. The delivery of the bursts and therecalculated time remaining are then used at block 280, where datarelated to one or more of the delivered therapy, triggering event andrate are stored in a memory, and the display of information to the useris updated. The display update may include updating the displayedvoltage, current and/or impedance information described both above andbelow. The method next determines whether the therapy regimen has beencompleted, as indicated at 282, and either returns 284 to block 270 toawait a next trigger, or exits at 286.

FIG. 7 illustrates a graphic display showing trigger parameters, safetylimits and safety controls for an electrosurgical signal generator, andcorresponds to area 7 of FIG. 1. In the illustrative example, thegraphic display shows trigger-related information and controls at 300.The use of an external trigger can be enabled or disabled by a toggleicon at 302. Details of the trigger implementation may include a delayfollowing the trigger signal at 304, a minimum delay period 306 before anext trigger will be recognized at 306, and parameters of the triggerincluding signal strength and polarity controls 308, which may allow theuser to select parameters related to the cardiac or other signal that isbeing tracked. The user can set, for example, the delays defined at 304and/or 306, as well as the type of trigger (rising, falling, peak, etc.)and trigger level 308. In other examples, the controls at 308 may beomitted, and the cardiac signal detection algorithm of a cardiac monitorused to issue the trigger signal may be relied upon instead. In stillother examples, a temperature trigger may be used by setting a maximumtemperature at which therapy can be initiated, for example.

The system may include automated adjustment of trigger parameters ifdesired. For example, the system may automatically adjust the burstdelay after trigger at 304 to extend the delay at lower pulse rates, orshorten the delay at higher pulse rates, if desired. In some examples,the system may determine a cardiac signal amplitude and use such anamplitude or average amplitude to adjust the trigger level at 308. Forexample, the system may calculate an average cardiac signal amplitudeover time, or a background noise amplitude, and may set the triggerlevel higher when the average signal amplitude or background noiseamplitude are higher, or lower the trigger level when the average signalamplitude or background noise amplitude are lower, to reduce thelikelihood of false triggering and/or failure to trigger whenappropriate.

Several safety limits are illustrated in FIG. 7 including a time limitfor therapy at 310, which ensure the device cannot be left on for anextended period of time; when the time limit expires, the HV system ofthe electrosurgical apparatus will power down and the user may receiveaudible and/or visual notifications. A maximum current threshold can beset at 312, as desired, such as by reference to a maximum rating of theprobe to be used with the system (in the event of a smartprobe system,the maximum current may be automatically set or limited to a valuerelated to the probe capabilities). An icon for disabling the signaloutput is provided at 314 and may be used to “pause” therapy deliveryuntil selected a second time. This may be used if it is determined thatthe probe needs repositioning, or the triggering signal capture device(such as several ECG electrodes) require repositioning, for example. Anall stop button 316 is also provided and may initiate complete shutdownof the system, for example, in the event of a system fault.

The display also provides file names for one or more data files that logtherapy delivery, as shown at 318. In an example, two log files may bemaintained, with one log file accessible to the operator for observing,in simpler form, therapy progress and any events that took place duringtherapy. This “clinician” log file may contain single or few parametersfor the pulses delivered during therapy, such as providing one or moreof average, peak, and/or minimum voltage, current, or impedance forrepresentative therapy pulses (i.e., the first pulse of each burst, fora first pulse for each electrode combination used in a burst) oraverages across bursts, either generally or broken out for individualelectrode combinations/polarities. An “engineering” log file may containmore comprehensive data, such as a point-by-point sampling of voltage,current and/or impedance of each pulse delivered during a therapyregimen, as well as internal values for various components to allow theengineering team to determine both a very detailed therapy output forthe regimen, as well as how the electrosurgical apparatus performedduring therapy. The engineering log file may contain a representation ofthe therapy signal, in raw or unprocessed form, or in a compressedformat, for example. For example, with a given therapy regimen, theclinician log file may omit information about the droop experienced bythe HV signal source during delivery of therapy bursts, while theengineering log file may contain HV signal source data, which can beuseful to diagnose performance of the HV circuitry and whether anybattery or capacitor elements, switches, etc. need replacement. Anytrigger signal information may be included in one or both of the logfiles. For example, a clinician log file may include data indicatingwhen trigger signals were identified, while the engineering log file mayinclude the captured ECG signal in its entirety (unprocessed orcompressed, as desired), to allow an assessment of whether triggeringwas performed correctly relative to the ECG signal itself.

FIG. 8 illustrates another user interface for an electrosurgicalapparatus. Area 9 illustrates a user-selectable control forautomatically reducing the output voltage without interrupting therapy,and is further explained with reference to FIG. 9 and FIGS. 10A-10B.Area 11 shows a simple approach to electrode selection usable inparticular with the simplified monophasic or biphasic therapy outputconfigurations of the user interface, and is further explained withreference to FIGS. 11A-11 b.

FIG. 9 highlights a feature of a user interface with reference to FIG.8. In the example, the control is named the “Capacitor Bank Tap” control350, and allows the user to switch a system output from using a full HVcapacitor bank voltage as the output signal control, to using less thanthe whole bank of capacitors. For example, if four capacitors areprovided, the user may tap on the Capacitor Bank Tap to select a taplocation chosen from 100% (four series capacitors output), 75% (three offour series capacitors), 50% (two of four series capacitors output) or25% (one of four series capacitors output). In other examples, differentquantities of capacitors may be used to generate other control levels.An example using a capacitor bank tap is shown in FIG. 10A. In analternative example, the selector here may have a slider bar allowingthe user to choose a percentage of the output to use by triggering astep down circuit as shown in FIG. 10B.

FIGS. 10A-10B show illustrative circuitry facilitating the feature ofFIG. 9. Starting with FIG. 10A, an example with a three capacitor bankis shown, with the HV stack shown at 360 and having each of 100% tap362, 66% tap 364, and 33% tap 366, selectable using a selection block368, which may be a set of high power switches. With the availability ofdifferent output taps on the capacitive circuit, the HV charger 370 maybe configured to couple to each capacitor individually. The use ofappropriately placed diodes and switches will allow the capacitors tobe, in effect, charged in parallel and discharged in series, which inturns allows the capacitors to be kept equally charged so that the useof a subset of the capacitor stack 360, omitting one or more capacitors,will not create an imbalance among the capacitors, distorting the tapselection math. For example, a triple-tapped transformer, gated in aflyback transformer configuration, may be used to charge the threecapacitors in the stack 360 using a primary phase to store energy in thetransformer and a secondary phase to discharge the stored energy to thecapacitor stack 360. When one capacitor has less voltage stored than theother two capacitors, the current from the transformer will be directedto the capacitor having the lowest voltage as it will present the leastimpedance to the secondary phase discharge current.

While a single HV charger 370 is shown, in other examples, a pluralityof capacitors can be provided with two or more HV chargers 370configured to charge individual ones, or combinations of two or more,capacitors 360. Rather than arrangement in a stack, the capacitors canbe provided separately, each referenced to ground as desired.Arrangements of additional switches may be provide in the selectionblock 368, and/or between the individual capacitors and the HV charger370 and/or ground, to enable flexible use of the capacitors in anyarrangement desired.

FIG. 10B shows another example. Here, an HV charging circuit 380 iscoupled to a capacitor stack 382. A step down circuit 384 can beselectively activated to provide a reduced voltage from the capacitorstack to a selector 386, which is used to route either the completecapacitor stack voltage to the therapy outputs, or the stepped-downvoltage from the step down circuit 384. A hybrid circuit may use both astep down 384 and a selectable capacitor stack tap to provide reducedoutputs with precision, while reducing the amount of voltage the stepdown circuit 384 has to handle.

In some examples, additional arrangements of switches may be used toallow capacitors to be linked together in additional ways. For example,a set of three capacitors can be used and linked together with twocapacitors in series, charged using a first HV charger 380, and a thirdcapacitor in parallel with the two capacitors and charged using a secondHV charger 380. The combination of two capacitors in series, with athird capacitor parallel to the first two capacitors, would allow atailored output pulse of higher capacitance than if the third capacitoris omitted, flattening the output pulse. With the same elements, thethree capacitors may instead be linked together in series, yielding alower capacitance to the total stack and causing the output therapy asdelivered to have a greater slope when therapy is delivered.

In another example, an electrosurgical generator may have 4, 6, or morehigh power capacitors adapted for therapy delivery purposes. Thecapacitors can then be divided into two or more groups, with each groupcharged to a selected power level sufficient to provide a burst oftherapy, with or without a desired degree of decay within individualpulses or across a burst of therapy. The groups of capacitors may beused in an alternating fashion, such that as a first group of capacitorsis used to deliver a first therapy burst, a second group is charged bythe HV charger. A second therapy burst can then be delivered using thesecond group of capacitors, while the HV charger recharges the firstgroup of capacitors.

Periodic tests may be run on the capacitors to ensure that each one isoperating properly. If a capacitor is found to be no longer operatingwithin set bounds, switches coupling that capacitor to the rest of thesystem may be opened until maintenance is performed, effectively lockingout the non-conforming capacitor. A flag or alert to the user may be setif a capacitor is not functioning correctly. A periodic test may be, forexample, performed by charging a capacitor to a predetermined level andmonitoring the voltage stored on the capacitor for a period of time todetermine a leakage rate associated with the capacitor, followed bydischarge of the capacitor into a known load (a passive resistor, forexample) to calculate the internal impedance of the capacitor and/or itseffective capacitance. The calculated leakage, internal impedance, andeffective capacitance can then be used to determine if the capacitor isoperating within functional boundaries. Such tests may be performed aspart of an initialization, turn-on, and/or warmup sequence for anelectrosurgical generator.

FIGS. 11A-11B highlight features of a user interface with reference toFIG. 8. Here the user is provided, on the graphical display, the optionto select and identify individual electrodes of a probe as anodes andcathodes, or disabled. For example, a single pair of anode and cathodemay be selected as shown at FIG. 11A, or a setup of two anodes and twocathodes may be used as shown at FIG. 11B. Unbalanced combinations maybe used, if desired, with two or three anodes and one cathode, or two orthree cathodes and one anode, instead.

FIG. 12 illustrates in block form an electrosurgical apparatus. Theapparatus contains a controller 400 which may be, for example, a statemachine, a microcontroller or microprocessor adapted to executeprogrammable instructions, which may be stored in a memory 420 that canalso be used to store history, events, parameters, sensed conditions,alerts, and a wide variety of data such as template programs,information related to probes 480, and the like. The memory 420 mayinclude both volatile and non-volatile memory types, and may include aport for coupling to a removeable memory element such as an SD card orthumb drive using a USB port. The stored instructions can be selected,configured or adjusted by a user to define, for example and withoutlimitation, therapy characteristics including pulse width, pulseamplitude, phase details (number of phases and type, as well asinterphase delay), pulse and burst repetition rates, pulse shape, pulsequantity in each burst, burst repetition rate, and pulse type (current,voltage, power, energy controlled) and shape (square wave, decaying,ramped, etc.) The stored instructions may also define how pulses change,if at all, during a burst (such as by increasing or decreasing amplitudefrom a first pulse of a burst to the second and subsequent pulses).

The controller 400 is coupled to a display 410 and user input 412. Thedisplay 410 and user input 412 may be integrated with one another byincluding a touchscreen. The display 410 may be a computer screen and/ortouchscreen and may also include lights and speakers to provideadditional output statuses or commands, verbal prompts, etc. The userinput 412 may include one or more of a keyboard, a mouse, a trackball, atouchpad, a microphone, a camera, etc. Any inputs by the user may beoperated on by the controller 400. The controller 400 may include one ormore application specific integrated circuits (ASICs) to provideadditional functionality, such as an ASIC for filtering and analyzing anECG for use as a trigger signal, or analog to digital conversioncircuits for handling received signals from a probe apparatus.

The controller 400 is also coupled to an HV Power block 430, which maycomprise a capacitor stack or other power storage apparatus, coupled toa charger or voltage multiplier that provides a step up from standardwall power voltages to very high powers, in the hundreds to thousands ofvolts. A therapy delivery block 440 is shown as well and may includehigh power switches arranges in various ways to route high voltages orcurrents from the HV power 430 to a probe input/output (Probe I/O) 470,which in turn couples to a probe 480. In some examples, the HV powerblock 430 and Delivery block 440 may incorporate circuitry and methodsdescribed in U.S. patent application Ser. No. 16/818,035, filed Mar. 13,2020 and titled WAVEFORM GENERATOR AND CONTROL FOR SELECTIVE CELLABLATION, the disclosure of which is incorporated herein by reference.

The Probe I/O 470 may include a smart probe interface that allows it toautomatically identify the probe 480 using an optical reader interface(barcode or QR code) or using an RFID chip that can be read via an RFreader, or a microchip that can be read once the probe 480 iselectrically coupled to a port on the Probe I/O 470. A measuring circuit472 is coupled to the Probe I/O 470, and may be used to measurevoltages, currents and/or impedances related to the probe, such asmeasuring the current flowing through a connection to the probe 480, orthe voltage at an output of the Probe I/O 470. The Probe I/O maycomprise electrical couplings to the Probe 480 for purposes of therapydelivery, or for sensing/measurement of signals from the Probe 480,using for example sensing electrodes or sensing transducers (motion,sound, vibration, temperature or optical transducers, for example), aswell as an optical I/O if desired to allow the output or receipt ofoptical energy, such as using optical interrogation of tissue or issuinglight at therapeutic levels or even at ablation power levels. Not all ofthese options are required or included in some embodiments.

The controller 400 is also coupled to trigger circuitry 460 and/orcommunications circuitry 462. The trigger circuitry may include, forexample, an ECG coupling port that is adapted to receive electrodes oran ECG lead system 464 for capturing a surface ECG or other signal fromthe patient for use in a triggered therapy mode. A communicationscircuit 462 may instead be used to wirelessly obtain a trigger signal,either a trigger that is generated externally, or a raw signal (such asan ECG) to be analyzed internally by the controller 400. Thecommunication circuit 462 may include a transceiver having one or moreof Bluetooth or WIFI antennas and driver circuitry to wirelesslycommunicate status, data, commands, etc. before, during or after therapyregimens are performed. If desired, the trigger 460 may have a dedicatedtransceiver itself, rather than relying on the system communicationblock 460.

The ECG electrodes, if provided, may be placed on the chest of thepatient, for example, in predetermined positions for capturing thepatient's cardiac signal. Suitable ECG electrode positions may be thosethat preferentially capture ventricular activity (the R-wave orventricular depolarization, associated with what is colloquially knownas the heart beat), though in some examples the ECG electrodes maypositioned to capture any portion of the cardiac signal, including forexample both atrial and ventricular signals. If a communication circuitis used, communication may be to a separate ECG detector. The “ECGdetector” may be a device that only senses cardiac signals, or it may beintegrated into a cardia pacing unit or a defibrillator device. Any suchsystem that can be used for wired or wireless communication to thetrigger circuitry may be used. In some examples, the patient may receivepacing therapy during a therapy session to control heart rate in apredictable fashion, such as by pacing at a rate that exceeds thepatient's intrinsic rhythm rate and/or resting heart rate, ensuringpredictable cardiac rate and signal characteristics.

The probe 480 may take any suitable form, such as a Leveen needle, or aprobe as shown in U.S. Pat. Nos. 5,855,576, 6,638,277, and/or US PG Pat.Pub. No. 2019/0223943, the disclosure of which is incorporated herein byreference, or other suitable ablation designs such as using multipleprobes each comprising a needle electrode, either integrated into onestructure or separately placed. The probe 480 may include one or moreindifferent or return electrodes, such as plates that can be cutaneouslyplaced.

A first illustrative and non-limiting embodiment takes the form of anelectrosurgical generator (such as, for example, the generator shown inFIG. 12) comprising: one or more ports adapted to receive one or moreelectrosurgical probes (such described with respect to block 470), eachport comprising at least one contact; a high voltage power source (suchas described with respect to block 430); delivery means for selectivelyrouting an output from the power source to selected contacts of the oneor more ports (such as the circuitry described with reference to block440 of FIG. 12); a controller having stored instructions that can beselected, configured or adjusted by a user (such as a controller asshown at 400 in FIG. 12, having access to stored instructions of thememory 420 or accessible using a communications block 462 having, forexample, Ethernet, USB, cellular, Bluetooth or WiFi communicationscapability, to off-device data storage), the stored instructionsincluding at least one instruction set for delivering a therapy regimen,the therapy regimen comprising a series of pulses each having a pulseamplitude and a pulse width, the series of pulses forming a burst, theinstruction set defining the pulse amplitude, the pulse width, how manypulses are in each burst, and how many bursts are to be delivered in thetherapy regimen and, optionally, a pulse repetition rate or burstrepetition rate (Several examples are shown in various figures; withoutlimiting to one example, FIG. 4A shows such a burst in the program blockfor sensed voltage at 50, in which example there are two pulses in aburst as defined at 40, each pulse having an amplitude and pulse width,with the number of bursts to be delivered at 46); and a user interfacehaving a user operable change means that the user can actuate to modifythe pulse amplitude without stopping or interrupting the therapy regimen(such a change means is shown in FIGS. 8-9, with full amplitudedelivered as shown at 9 in FIG. 8, and a fraction of the full amplitudedelivered when the user interface is actuated as shown in FIG. 9).Additionally or alternatively, the high voltage power source comprisesat least first and second capacitors placed in series for purposes ofoutputting therapy pulses, and stack selection means, wherein the stackselection means is controlled by the user operable change means toinclude all or less than all of the capacitors in the series forpurposes of outputting therapy pulses (FIG. 10A shows this configurationwith at least two capacitors, three being illustratively shown, and astack selection means at 368 to select all or a part of the stack).Additionally or alternatively, the electrosurgical generator of claim 1wherein the high voltage power source comprises step down meanscontrolled by the user operable change means to route a higher or lowervoltage from the high voltage power source to the delivery means. Asnoted previously, the electrosurgical system may be configured todefine, control, and/or display therapy in terms of voltage, current,power, and/or energy, as desired, including, optionally, by the use ofconstant voltage, power, current, and/or energy therapy delivery.

A second illustrative and non-limiting embodiment takes the form of anelectrosurgical generator (such as, for example, the generator shown inFIG. 12) comprising: one or more ports adapted to receive one or moreelectrosurgical probes (such described with respect to block 470), eachport comprising at least one contact; a high voltage power source (suchas described with respect to block 430); delivery means for selectivelyrouting an output from the power source to selected contacts of the oneor more ports (such as the circuitry described with reference to block440 of FIG. 12); a controller having stored instructions that can beselected, configured or adjusted by a user (such as a controller asshown at 400 in FIG. 12, having access to stored instructions of thememory 420 or accessible using a communications block 462 having, forexample, Ethernet, USB, cellular, Bluetooth or WiFi communicationscapability, to off-device data storage), the stored instructionsincluding at least one instruction set for delivering a therapy regimen,the therapy regimen defining a multi-polar output sequence in which atleast three electrodes are used, with a first selection of theelectrodes used to deliver a first pulse and a second selection of theelectrodes, different from the first selection of the electrodes, usedto deliver a second pulse (FIGS. 1 and 4C each show a three electroderotating therapy configuration in which groups of three pulses aredelivered in sequence using different electrode pairs for each of thethree pulses—see FIG. 4C at 140); measurement means for measuringimpedance during delivery of a therapy pulse (such as block 472 asdescribed relative to FIG. 12); a user interface configured fordisplaying therapy delivery parameters during or after generation of thetherapy regimen, the user interface displaying the amplitude of thefirst pulse and the second pulse in a first portion of the userinterface and impedance encountered by the first pulse and the secondpulse in a second portion of the user interface, to facilitatecomparison of the first pulse and second pulse amplitudes and impedances(See FIGS. 1 and 4C, showing a user interface facilitating such acomparison).

Additionally or alternatively to either of the first and secondillustrative, non-limiting embodiments, the electrosurgical generatormay also comprise a trigger means adapted to sense or receive arepresentation of a cardiac signal of a patient, the trigger meansconfigured to identify a therapy window for delivery of a burst fromwithin the therapy regimen, wherein the delivery means is responsive tothe trigger means to issue a therapy burst (as shown and described withreference to block 460 in FIG. 12).

A third illustrative and non-limiting embodiment takes the form of anelectrosurgical generator (such as, for example, the generator shown inFIG. 12) comprising: one or more ports adapted to receive one or moreelectrosurgical probes (such described with respect to block 470), eachport comprising at least one contact; a high voltage power source (suchas described with respect to block 430); delivery means for selectivelyrouting an output from the power source to selected contacts of the oneor more ports (such as the circuitry described with reference to block440 of FIG. 12); a controller having stored instructions that can beselected, configured or adjusted by a user (such as a controller asshown at 400 in FIG. 12, having access to stored instructions of thememory 420 or accessible using a communications block 462 having, forexample, Ethernet, USB, cellular, Bluetooth or WiFi communicationscapability, to off-device data storage), the stored instructionsincluding at least one instruction set for delivering a therapy regimen,the therapy regimen comprising a series of pulses each having a pulseamplitude and a pulse width, the series of pulses forming a burst, theinstruction set defining the pulse amplitude, the pulse width, how manypulses are in each burst, and how many bursts are to be delivered in thetherapy regimen (Several examples are shown in various figures; withoutlimiting to one example, FIG. 4A shows such a burst in the program blockfor sensed voltage at 50, in which example there are two pulses in aburst as defined at 40, each pulse having an amplitude and pulse width,with the number of bursts to be delivered at 46); a trigger meansadapted to sense or receive a triggering signal from a patient, thetrigger means configured to identify a therapy window for delivery of aburst defined by the therapy regimen (such as shown and described withreference to block 460 of FIG. 12); and timing means configured todetermine time remaining for the therapy regimen comprising rate meansfor determining a trigger rate using data from the trigger means, andcalculating means for determining how much time will be required tocomplete all bursts of the therapy regimen in light of the trigger rate(the timing means may include a stored instruction set operable by thecontroller 400 configured to perform as illustrated in FIG. 15 at blocks276 and 278); and display means for displaying to a user an estimatedremaining time as calculated by the timing means (See, for example,FIGS. 1 and 6, with the estimated time remaining shown at 252 and 254 inFIG. 6, details that may be shown at area 6 in FIG. 1).

Additionally or alternatively, the trigger means may use a cardiacsignal and comprises a lead system having ECG electrodes thereon forcapturing a cutaneous cardiac signal from a patient and a cardiac signaldetector for detecting components of the cardiac signal (See FIG. 12, at464). Additionally or alternatively, the trigger means uses a cardiacsignal and comprises or is coupled to a transceiver for receiving awireless signal from an ECG detector representing a patient's cardiacsignal, and a cardiac signal detector for detecting components of thecardiac signal (See FIG. 12, at 460 and 462; as described above, thetransceiver of the system communication block 462 may be accessed by thetrigger 460, or the trigger 460 may have its own transceiver).

Additionally or alternatively, the user interface allows the user toselect a delay period for the trigger means to use to delay the start ofa therapy burst relative to a triggering signal (such a user interfaceis shown in FIG. 7, with the burst delay defined at 304). Additionallyor alternatively, the user interface comprises an amplitude displayallowing the user to set or adjust therapy amplitude and, in conjunctionwith the amplitude display, an estimate of the amplitude that will bedelivered to tissue between a selected pair of electrodes on a probecoupled to the one or more ports (FIG. 1, area 3; FIG. 3, showing theprogrammed voltage at 34 and the estimated delivered voltage at 32).Additionally or alternatively, the user interface comprises a waveformselector allowing a user to select from at least biphasic and monophasicwaveform types (FIG. 1, area 2; see FIG. 2 showing this structure as adrop-down list).

Additionally or alternatively, the user interface comprises a waveformdesign tool allowing a user to select electrodes to be used whendelivering a pulse, an interval between pulses in each burst, a quantityof pulses to provide in each burst, and a quantity of bursts to deliver(FIGS. 4A-4C each show such user interface tools on the left side ofeach Figure), and the controller is responsive to the waveform designtool to select, configure, or adjust an instruction set defining thetherapy regimen, wherein the waveform design tool allows the user tovary the electrodes from one pulse to the next (FIG. 4C shows such aswaveform design tool, as does FIGS. 14A-14B).

Additionally or alternatively, the electrosurgical generator maycomprise recording means for storing first and second therapy logs asfollows: the first log comprising input and output parameters of therapyas delivered; and a second log recording raw or unprocessed waveforms asdelivered to the patient (FIG. 7, element 318 shows the two log filenames; associated text above describes such operations). Additionally oralternatively, the user interface comprises a pause button or iconoperable to interrupt a therapy regimen without terminating the therapyregimen (Area 7 in FIG. 1; FIG. 7 shows inclusion of two controls at 314to disable or pause the signal, without cancelling, and a stop button316 to fully cease therapy and terminate the therapy regimen).

Some examples comprise a system for treating a patient by ablation of atarget tissue comprising an electrosurgical generator as in any of thefirst, second or third illustrative, non-limiting embodiments, and anyvariant thereof, in combination with a probe configured for use with theelectrosurgical generator (FIG. 12, block 480).

Each of these non-limiting examples can stand on its own, or can becombined in various permutations or combinations with one or more of theother examples.

The above detailed description includes references to the accompanyingdrawings, which form a part of the detailed description. The drawingsshow, by way of illustration, specific embodiments in which theinvention can be practiced. These embodiments are also referred toherein as “examples.” Such examples can include elements in addition tothose shown or described. However, the present inventors alsocontemplate examples in which only those elements shown or described areprovided. Moreover, the present inventors also contemplate examplesusing any combination or permutation of those elements shown ordescribed (or one or more aspects thereof), either with respect to aparticular example (or one or more aspects thereof), or with respect toother examples (or one or more aspects thereof) shown or describedherein.

In the event of inconsistent usages between this document and anydocuments so incorporated by reference, the usage in this documentcontrols. In this document, the terms “a” or “an” are used, as is commonin patent documents, to include one or more than one, independent of anyother instances or usages of “at least one” or “one or more.” Moreover,in the following claims, the terms “first,” “second,” and “third,” etc.are used merely as labels, and are not intended to impose numericalrequirements on their objects.

Method examples described herein can be machine or computer-implementedat least in part. Some examples can include a computer-readable mediumor machine-readable medium encoded with instructions operable toconfigure an electronic device to perform methods as described in theabove examples. An implementation of such methods can include code, suchas microcode, assembly language code, a higher-level language code, orthe like, stored in a non-transitory medium. Such code can includecomputer readable instructions for performing various methods. The codecan be tangibly stored on one or more volatile, non-transitory, ornon-volatile tangible computer-readable media, such as during executionor at other times. Examples of these tangible computer-readable mediacan include, but are not limited to, hard disks, removable magnetic oroptical disks, magnetic cassettes, memory cards or sticks, random accessmemories (RAMs), read only memories (ROMs), and the like.

The Abstract is provided to comply with 37 C.F.R. § 1.72(b), to allowthe reader to quickly ascertain the nature of the technical disclosure.It is submitted with the understanding that it will not be used tointerpret or limit the scope or meaning of the claims. The abovedescription is intended to be illustrative, and not restrictive. Forexample, the above-described examples (or one or more aspects thereof)may be used in combination with each other. Other embodiments can beused, such as by one of ordinary skill in the art upon reviewing theabove description.

In the Detailed Description, various features may be grouped together tostreamline the disclosure. This should not be interpreted as intendingthat an unclaimed disclosed feature is essential to any claim. Rather,inventive subject matter may lie in less than all features of aparticular disclosed embodiment. The following claims are herebyincorporated into the Detailed Description as examples or embodiments,with each claim standing on its own as a separate embodiment. Suchembodiments can be combined with each other in various combinations orpermutations. The scope of the invention should be determined withreference to the appended claims, along with the full scope ofequivalents to which such claims are entitled.

The claimed invention is:
 1. An electrosurgical generator comprising:one or more ports adapted to receive one or more electrosurgical probes,each port comprising at least one contact; a high voltage power source;delivery circuitry comprising a plurality of switches configured toroute an output from the power source to selected contacts of the one ormore ports; a controller having stored instructions that can beselected, configured or adjusted by a user, the stored instructionsincluding at least one instruction set for delivering a therapy regimen,the therapy regimen comprising a plurality of pulses each having a pulseamplitude and a pulse width, the instruction set defining the pulseamplitude and the pulse width; and a user interface having a useroperable change tool that the user can actuate to modify the pulseamplitude without stopping or interrupting the therapy regimen.
 2. Theelectrosurgical generator of claim 1 wherein the high voltage powersource comprises at least first and second capacitors configured foroutputting therapy pulses, and a stack selector comprising a pluralityof switches responsive to the change tool to include, in a firstconfiguration, all of the capacitors for purposes of outputting therapypulses, and in a second configuration, less than all of the capacitorsfor purposes of outputting therapy pulses.
 3. The electrosurgicalgenerator of claim 1 wherein the high voltage power source is coupled toa voltage step down circuit responsive to the change tool to route ahigher or lower voltage from the high voltage power source to thedelivery circuitry.
 4. An electrosurgical generator as in claim 1wherein the instruction set for delivering the therapy regimen comprisesa series of pulses grouped as a burst, the therapy regimen defining howmany pulses are in a burst, wherein the controller further comprises anexecutable triggering instruction set adapted to receive or identify atherapy trigger, identify a therapy window for delivery of a therapyburst from within the therapy regimen relative to the therapy trigger,and instruct the delivery circuit to route a therapy burst to selectedcontacts of the one or more ports.
 5. An electrosurgical generator as inclaim 1 wherein the instruction set for delivering the therapy regimencomprises a series of pulses grouped as a burst, the therapy regimendefining how many pulses are in a burst, further comprising a triggercircuit adapted to sense or receive a representation of a cardiac signalof a patient, identify a therapy window for delivery of a therapy burstfrom within the therapy regimen, and instruct the delivery circuit toroute a therapy burst to selected contacts of the one or more ports. 6.An electrosurgical generator as in claim 1 wherein instruction setdefines each of pulse amplitude, pulse width, how many pulses are ineach burst, how many bursts are to be delivered in the therapy regimen,a pulse repetition rate and a burst repetition rate.
 7. Anelectrosurgical generator comprising: one or more ports adapted toreceive one or more electrosurgical probes, each port comprising atleast one contact; a high voltage power source; delivery circuitrycomprising a plurality of switches configured to route an output fromthe power source to selected contacts of the one or more ports; acontroller having stored instructions that can be selected, configuredor adjusted by a user, the stored instructions including at least oneinstruction set for delivering a therapy regimen, the therapy regimendefining a multi-polar output sequence in which at least threeelectrodes are used, with a first selection of the electrodes used todeliver a first pulse and a second selection of the electrodes,different from the first selection of the electrodes, used to deliver asecond pulse; a measurement circuitry configured to measure impedanceduring delivery of a therapy pulse including one or more of a currentsensor or a voltage sensor; a user interface configured for displayingtherapy delivery parameters during or after generation of the therapyregimen, the user interface displaying in the amplitude of the firstpulse and the second pulse in a first portion of the user interface andimpedance encountered by the first and second pulses in a second portionof the user interface, to facilitate comparison of the first and secondpulse amplitudes and impedances.
 8. An electrosurgical generator as inclaim 7 wherein the controller further comprises an executabletriggering instruction set adapted to sense or receive a representationof a cardiac signal of a patient, identify a therapy window for deliveryof a therapy burst from within the therapy regimen, and instruct thedelivery circuit to route a therapy burst to selected contacts of theone or more ports.
 9. An electrosurgical generator as in claim 7 furthercomprising a trigger circuit adapted to sense or receive arepresentation of a cardiac signal of a patient, identify a therapywindow for delivery of a therapy burst from within the therapy regimen,and instruct the delivery circuit to route a therapy burst to selectedcontacts of the one or more ports.
 10. A system for treating a patientby ablation of a target tissue comprising an electrosurgical generatoras in claim 7, and a probe configured for use with the electrosurgicalgenerator.
 11. An electrosurgical generator comprising: one or moreports adapted to receive one or more electrosurgical probes, each portcomprising at least one contact; a high voltage power source; deliverycircuitry comprising a plurality of switches configured to route anoutput from the power source to selected contacts of the one or moreports; a controller having stored instructions that can be selected,configured or adjusted by a user, the stored instructions including atleast one instruction set for delivering a therapy regimen, the therapyregimen comprising a series of pulses each having a pulse width, theseries of pulses forming a burst, the instruction set defining how manypulses are in each burst and defining how many bursts are to bedelivered in the therapy regimen; a trigger adapted to sense or receivea triggering signal from a patient, the trigger configured to identify atherapy window for delivery of a burst defined by the therapy regimenand command the delivery circuitry to route the output to selectedcontacts during the therapy window, wherein the controller furtherincludes a stored timer instruction set adapted to determine timeremaining for the therapy regimen by determining a trigger rate usingdata from the trigger, and calculate how much time will be required tocomplete remaining bursts of the therapy regimen in light of the triggerrate; and a user interface having a display section that displays to auser an estimated remaining time as calculated by the controllerexecuting the stored timer instruction set.
 12. An electrosurgicalgenerator as in claim 11 wherein the trigger is a dedicated circuit anda lead system having ECG electrodes thereon for capturing a cutaneouscardiac signal from a patient, the dedicated circuit including a cardiacsignal detector for detecting components of the cardiac signal andthereby detecting cardiac cycles.
 13. An electrosurgical generator as inclaim 11 wherein the trigger is a stored trigger instruction setoperable by the controller, the electrosurgical generator comprising awireless transceiver comprising an antenna, amplifier, and demodulatorto facilitate receipt of a wireless signal from an ECG detector issuingcardiac signal related data including indications of when a selectedcomponent of the cardiac signal occurs, wherein the controller isconfigured to receive cardiac signal related data from the wirelesstransceiver while executing the stored trigger instruction set.
 14. Anelectrosurgical generator as in claim 11 wherein the trigger isconfigured to wait for expiration of user configurable delay periodafter a triggering signal is observed or received before the therapywindow, and the user interface allows the user to select theconfigurable delay period.
 15. An electrosurgical generator as in claim11 wherein the user interface comprises an amplitude display allowingthe user to set or adjust therapy amplitude and, in conjunction with theamplitude display, the user interface is also adapted to display anestimate of the amplitude that will be delivered to tissue between aselected pair of electrodes on a probe coupled to the one or more ports.16. An electrosurgical generator as in claim 11 wherein the userinterface comprises a waveform selector allowing a user to select fromat least biphasic and monophasic waveform types.
 17. An electrosurgicalgenerator as in claim 11 wherein the user interface comprises a waveformdesign tool allowing a user to select an interval between pulses in eachburst, a quantity of pulses to provide in each burst, and a quantity ofbursts to deliver, and the controller is responsive to the waveformdesign tool to select, configure, or adjust an instruction set definingthe therapy regimen.
 18. An electrosurgical generator as in claim 11wherein the controller is configured to store first and second therapylogs for delivery of the therapy regimen as follows: the first logcomprising input and output parameters of therapy as delivered; and thesecond log recording waveforms as delivered to the patient.
 19. Anelectrosurgical generator as in claim 11 wherein the user interfacecomprises a pause button or icon operable to interrupt a therapy regimenwithout terminating the therapy regimen.
 20. A system for treating apatient by ablation of a target tissue comprising an electrosurgicalgenerator as in claim 11, and a probe configured for use with theelectrosurgical generator.